What are the different uses of sulfur

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Sulfur exists in very different allotropic modifications, the most important of which are characterized in the various states of aggregation below:

Under normal conditions, the rhombic sulfur (α-sulfur) is the only thermodynamically stable form. α-sulfur occurs in crown-shaped, eight-membered rings.

Above 95.6 it converts to monoclinic sulfur (β-sulfur). The molecules in the crystal lattice are rearranged. The conversion speed is relatively slow.

At 119 the monoclinic sulfur melts to λ-sulfur. The rings now slowly transform into rings of different sizes, mainly n = 6, 7, 9, 12, but also up to n = 26; π-sulfur. The λ-sulfur melt is initially thin and yellow. At 154 there is a drastic increase in viscosity with the formation of polymeric μ-sulfur.

Above 185, the viscosity decreases as a result of increasing cracking, with the formation of diradical chain-like sulfur molecules.

At the boiling point 444.6, the melt is dark red-brown and thin. In the gas phase, there are temperature-dependent equilibria between molecules (n = 1-8). Only above 1,800 are there any significant amounts of sulfur atoms.

If liquid sulfur melts are quenched by pouring them into water, what is known as plastic sulfur is obtained, which mainly consists of λ- and µ-sulfur. It is tough, elastic and soluble in pyridine. The sulfur atom chains are arranged helically with approx. 10 atoms on three turns. There are right and left handed screws next to each other.